RIPE Region Hostcount FAQ
- What is a host?
- What is a real host?
- Why are you trying to do a zone transfer from my domain?
- Is there similar information for all TLDs, not just those in the RIPE NCC Service Region?
- Why does the number of hosts increase and decrease so much?
- What is the xx TLD?
For the purposes of Hostcount, a host is a domain name, such as a-host.a-com.de., sited at a leaf node of the domain name tree. In practice, all A records in the Domain Name System (DNS) are eligible to be counted as hosts, but many are discarded, for instance because they have already been seen elsewhere.
A real host is a non-duplicate host. The number of real hosts for a particular TLD is equal to the counted hosts minus the number of duplicate hosts. Duplicate hosts are those hosts that have already counted during the Hostcount.
The zone transfer is an integral part of performing the RIPE NCC Region Hostcount. It is performed once at the end of each month for the purpose of generating summary statistics about the growth of the Internet.
The RIPE NCC apologises for any concern that may have been caused by an unexpected attempt at a zone transfer. We would be extremely grateful if you would enable zone transfers for requests originating from the address range 18.104.22.168/22.
If you have further questions or concerns, please contact: firstname.lastname@example.org.
The Internet Software Consortium carries out a survey of the entire Internet approximately every six months.
The RIPE NCC Hostcount is a Domain Name System (DNS) hostcount.
The following TLDs are historical and their hosts and zones should not increase dramatically:
- gb - Great Britain - now covered by uk
- su - Soviet Union - now covered by multiple TLDs
The Hostcount collects its data via zone transfers. Many organisations are increasingly wary of allowing zone transfers of their domain for security reasons. It's also possible that some organsations wish to restrict zone transfers due to the increased load on their nameserver.
The impact of restricting zone transfers for a zone is that all the data about the zone and its child zones is lost.
The two primary reasons for major decreases in the number of hosts counted for a TLD can be identified as:
A provider, whose nameserver runs secondary for many of its customers, decides to restrict zone transfers, either via the nameserver config or an Access Control List (ACL), so that the machine doing the Hostcount loses access to hundreds or thousands of small zones at the same time, each of which has a few hosts.
- An end-user/provider with a very large zone decides to restrict transfers so that all of the hosts in the zone are lost to the Hostcount.
Major increases in the number of hosts occur when there is no restriction.